Energy & Waste (Edexcel GCSE Physics): Revision Note

Generating Electricity

• The process by which electricity is produced in a nuclear power station is the same as for any other fuel-powered station – the only difference is the process used to produce the heat

• Nuclear fission produces a large quantity of heat which is carried away from the reactor by a coolant (usually pressurised water)

• The coolant is then used to heat a separate water source, turning the water into steam

  • A separate source is used in order to reduce the risk of contamination

• The steam is then used to drive turbines which then turn generators, producing electricity

How electricity is generated from a nuclear reactor

• The nuclear reactor is:

  • The part of the power station that provides thermal energy from fission chain reactions

• The boiler is:

  • The part of the power station that uses thermal energy to boil water to create steam

• The turbine is:

  • The part of the power station that uses steam to transfer thermal energy into kinetic energy

• The generator is

  • The part of the power station that transfers kinetic energy into electrical energy

• The condenser is:

  • The part of the power station that cools the steam back into water

Nuclear Waste

• The biggest problem concerning nuclear power is the waste that it produces

• This waste comprises of the unusable fission products from the fission of uranium-235 or from spent fuel rods

  • This is because each fission of a uranium-235 nucleus results in two smaller nuclei being produced

• This is by far the most dangerous type of waste as it will remain radioactive for thousands of years

  • These smaller (daughter) nuclei are both highly radioactive – more radioactive, in fact than the original fuel

• As well as being highly radioactive, the spent fuel roads are extremely hot and must be handled and stored much more carefully than the other types of waste

• Whilst the amount of waste produced (relative to the amount of energy generated) is fairly small, the waste is extremely dangerous

  • Therefore, it must be stored underground till they are no longer harmful

Nuclear waste is stored underground whilst the fission products are still radioactive